Folic acid (FA) also known as (N-[p-{[(2-amino-4-hydroxy-6-pteridinyl) methyl] amino} benzoyl]-L-glutamic acid), is a water soluble vitamin found in plants and animals. The deficiency of FA leads to an increased risk of various diseases like neural tube defects in newborn, cardiovascular disease, cancer, Alzheimer's disease and megaloblastic anemia. The normal levels of FA in human blood serum should fall in the range between 2 and 15 ng/mL. Present review article discusses the classification, principles, advantages and disadvantages of FA bio-sensing methods. FA biosensors operate within 3-300 s, in pH range, 1.8-7.8, concentration range 8.71 x 10(-9) mu M for FA. The FA biosensors displayed detection limits (LOD) between 1.6 x 10(-11) to 0.091 mu M and with working potential - 0.88 to 4.5 V. These biosensors measured FA level in various biological and pharmaceuticals samples.